"The Descriptive Register of Genuine Bank Notes" by Gwynne & Day is an extremely useful book for obsolete banknote collectors. It describes genuine obsolete notes (even some Canadian) in detail, that is, it describes the vignettes etc. I suspect that Haxby used this book heavily to describe notes that he did not see himself.
The original books are very difficult to obtain. Very few copies exist in libraries. The ANA library has 1859, 1860, and 1862 copies available for checkout to ANA members. See
http://207.67.203.79/A94000staff/opac/search/SimpleSearch.asp Google books does not have a free pdf version.
Fortunately a 1977 reprint of the 1862 edition is available typically for about $50. This is probably why google does not allow free downloads of this 19th century book.
There is presently one on ebay at about $11 but I suspect that it will sell for much more.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=380224382891&ssPageName=STRK:MEWAX:ITHere is one for $95:
http://www.upillar.com/listings/108628-obsolete-currency-confederate-currency-and-national-currency-books-for-sale